1. Field
Embodiments of the present application generally relate to a sheet processing device for performing predetermined processing on a conveyed sheet member and carrying it out, an image forming apparatus having the sheet processing device, such as a copying machine, a printer, a facsimile machine, a digital complex machine having these compound functions, and/or a sheet processing method employed by the sheet processing device.
2. Description of the Related Art
In the image forming apparatus, such as the copying machine and the printer, there have been advances in multifunction, so that an image forming apparatus having a memory storing a large amount of images for forming images every section has become the mainstream. Also, along with the advances in multifunction, an image forming apparatus comes into being that includes a sheet post-processing unit for performing post-treatment, such as stack processing for stacking recorded sheets on a discharge tray while sorting the sheets, staple processing for stapling every predetermined number of the sheets and stacking on the discharge tray, and punch processing for punching the sheets for filing.
Among them, in the sheet post-processing unit having a punch function for punching sheets, the punch processing unit is arranged at an intermediate portion of a sheet conveying path so as to punch sheet during conveying the sheet. The punch processing unit generally includes a unit in that a punch and a die are arranged to oppose each other with a sheet therebetween so as to punch the sheet during conveying the sheet by inserting the punch head into the hole of the die.
In such a sheet post-processing unit, a punch scrap storage box (storage part) is arranged below the punch processing unit for receiving dropping punch scraps. At an upper portion of the punch scrap storage box, a full-space detection sensor is generally provided for informing an operator about the full space prompting its handling when the box is fully filled with the scraps.
When the punch scraps are going to drop into the box, the punch scraps are heaped around the scrap dropping point (just under the punch processing unit) as a center, so that the scraps are heaped in a chevron shape around the scrap dropping point. At this time, the scraps are concentrated only in the vicinity of the scrap dropping point and the scraps are difficult to heap at places separated from the dropping point. As a result, the storing efficiency of the punch scrap storage box is reduced as well as the scraps are spilled out from the apex of the scrap heap due to the falling down.
Then, in the sheet post-processing unit, the flattening of the punch scraps has been performed within the punch scrap storage box.
The technique for flattening the punch scraps includes:
1) The punch scraps are flattened by knocking them from outside the punch scrap storage box to apply vibration them;
2) By providing a hopper pin or a sheet within the punch scrap storage box, the dropping punch scraps are dispersed not to concentrate on the center;
3) A mobile punch scrap flattening mechanism is provided between the punch processing unit and the punch scrap storage box for dispersing the dropping directions of the punch scraps. As such known techniques, there are several disclosed inventions.
Even when preventing the operational interference due to the punch scraps by flattening scraps in such manners or by promptly informing the full space to prompt an operator to clear out the punch scrap storage box by detecting the full space, the punch scrap storage box must be arranged just under the punch processing unit, so that for securing the storage capacity of the punch scrap storage box, the box is needed to be deep.
Hence, it is necessary to ensure a large space just under the punch processing unit. Additionally, it is difficult to arrange the punch processing unit on the downstream side of the sheet post-processing unit. Furthermore, when the punch processing unit is arranged in the inner part of the sheet post-processing unit, the punch scrap storage box with large capacity has to be also arranged in the inner part, reducing work efficiency when the box is dragged out of the sheet post-processing unit as well as limiting the layout in ensuring a large space for operation after the box is dragged out.